View Compilation Error

0_0_27234627_13375.cpp: In function 'int main()':
0_0_27234627_13375.cpp:11:5: error: 'cin' was not declared in this scope
     cin>>n;
     ^
0_0_27234627_13375.cpp:50:9: error: 'cout' was not declared in this scope
         cout<<"Case #"<<w<<": ";
         ^
0_0_27234627_13375.cpp:53:15: error: 'endl' was not declared in this scope
         cout<<endl;
               ^